1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
|
/*=========================================================================
*
* Copyright NumFOCUS
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0.txt
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*=========================================================================*/
// Software Guide : BeginLatex
//
// The following example illustrates how to use the
// \doxygen{BSplineInterpolateImageFunction} for resampling an image. In
// this particular case an \doxygen{AffineTransform} is used to map the input
// space into the output space.
//
// \index{itk::AffineTransform!resampling}
//
// Software Guide : EndLatex
#include "itkImage.h"
#include "itkImageFileReader.h"
#include "itkImageFileWriter.h"
#include "itkResampleImageFilter.h"
#include "itkBSplineInterpolateImageFunction.h"
// Software Guide : BeginLatex
//
// The header of the affine transform is included below.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
#include "itkAffineTransform.h"
// Software Guide : EndCodeSnippet
int
main(int argc, char * argv[])
{
if (argc < 4)
{
std::cerr << "Usage: " << std::endl;
std::cerr << argv[0] << " inputImageFile outputImageFile degrees"
<< std::endl;
return EXIT_FAILURE;
}
constexpr unsigned int Dimension = 2;
using InputPixelType = unsigned char;
using OutputPixelType = unsigned char;
using InputImageType = itk::Image<InputPixelType, Dimension>;
using OutputImageType = itk::Image<OutputPixelType, Dimension>;
using ReaderType = itk::ImageFileReader<InputImageType>;
using WriterType = itk::ImageFileWriter<OutputImageType>;
auto reader = ReaderType::New();
auto writer = WriterType::New();
reader->SetFileName(argv[1]);
writer->SetFileName(argv[2]);
const double angleInDegrees = std::stod(argv[3]);
// Software Guide : BeginLatex
//
// The Resampling filter is instantiated and created just like in previous
// examples. The Transform is instantiated and connected to the resampling
// filter.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
using FilterType =
itk::ResampleImageFilter<InputImageType, OutputImageType>;
auto filter = FilterType::New();
using TransformType = itk::AffineTransform<double, Dimension>;
auto transform = TransformType::New();
filter->SetTransform(transform);
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The salient feature of this example is the use of the
// \doxygen{BSplineInterpolateImageFunction}, which uses cubic BSplines in
// order to interpolate the resampled image.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
using InterpolatorType =
itk::BSplineInterpolateImageFunction<InputImageType, double>;
auto interpolator = InterpolatorType::New();
filter->SetInterpolator(interpolator);
filter->SetDefaultPixelValue(100);
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The parameters of the output image are taken from the input image.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
reader->Update();
const InputImageType::SpacingType & spacing =
reader->GetOutput()->GetSpacing();
const InputImageType::PointType & origin = reader->GetOutput()->GetOrigin();
const InputImageType::DirectionType & direction =
reader->GetOutput()->GetDirection();
InputImageType::SizeType size =
reader->GetOutput()->GetLargestPossibleRegion().GetSize();
filter->SetOutputOrigin(origin);
filter->SetOutputSpacing(spacing);
filter->SetOutputDirection(direction);
filter->SetSize(size);
// Software Guide : EndCodeSnippet
filter->SetInput(reader->GetOutput());
writer->SetInput(filter->GetOutput());
TransformType::OutputVectorType translation1;
const double imageCenterX = origin[0] + spacing[0] * size[0] / 2.0;
const double imageCenterY = origin[1] + spacing[1] * size[1] / 2.0;
translation1[0] = -imageCenterX;
translation1[1] = -imageCenterY;
transform->Translate(translation1);
std::cout << "imageCenterX = " << imageCenterX << std::endl;
std::cout << "imageCenterY = " << imageCenterY << std::endl;
const double degreesToRadians = std::atan(1.0) / 45.0;
const double angle = angleInDegrees * degreesToRadians;
transform->Rotate2D(-angle, false);
TransformType::OutputVectorType translation2;
translation2[0] = imageCenterX;
translation2[1] = imageCenterY;
transform->Translate(translation2, false);
// Software Guide : BeginLatex
//
// The output of the resampling filter is connected to a writer and the
// execution of the pipeline is triggered by a writer update.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
try
{
writer->Update();
}
catch (const itk::ExceptionObject & excep)
{
std::cerr << "Exception caught !" << std::endl;
std::cerr << excep << std::endl;
}
// Software Guide : EndCodeSnippet
return EXIT_SUCCESS;
}
|
